1. Field of the Invention
The present invention relates to a method and an apparatus for guiding value documents.
2. Related Art
Value documents are understood in this connection to be sheet-shaped objects that represent for example a monetary value or an authorization and hence should not be producible arbitrarily by unauthorized persons. Hence, they have features that are not easily produced, in particular copied, whose presence is an indication of authenticity, i.e. production by an authorized body. Important examples of such value documents are coupons, vouchers, checks and in particular bank notes.
Such value documents, in particular bank notes, are frequently checked by machine for authenticity and/or other properties, for example their state. Upon such a check the value documents, depending on the type of the value document processing apparatus employed for this purpose, can be transported in singled form at very high speed along a transport path on which sensors for checking value documents are arranged. For transport there are normally employed transport belts between which the value documents are clamped during transport. However, in particular for double-sided checking of value documents and/or for analyzing transmission properties it would be desirable to be able to guide the value documents without belts at least for certain stretches. A transport without belts has the disadvantage, however, that the value documents then move on the transport path only due to their inertia, so that disturbances can occur, for example through flutter motions of the value documents.
Such flutter motions can in principle also occur and impair the analysis of properties of the value documents upon belt transport. Flutter motions can further lead to value documents during transport touching the surfaces of parts on the transport path, for example sensor windows, which can result in wear thereof.